đây rồi...$TS=2sin2x+2sinx.cosx$$MS=2sin2x+2sin2x.sinx$$\Rightarrow BT=\frac{cosx+1}{sinx+1}=\frac{2cos^{2}\frac{x}{2}}{(sin\frac{x}{2}+cos\frac{x}{2})^{2}}=\frac{2}{(1+tan\frac{x}{2})^{2}}$*$sinx+1=2sin\frac{x}{2}cos\frac{x}{2}+sin^{2}\frac{x}{2}+cos^{2}\frac{x}{2}$
đây rồi...$T
ử S
ố=2sin2x+2sinx.cosx$$M
ẫu S
ố=2sin2x+2sin2x.sinx$$\Rightarrow BT=\frac{cosx+1}{sinx+1}=\frac{2cos^{2}\frac{x}{2}}{(sin\frac{x}{2}+cos\frac{x}{2})^{2}
*}=\frac{2}{(1+tan\frac{x}{2})^{2}}$*$sinx+1=2sin\frac{x}{2}cos\frac{x}{2}+sin^{2}\frac{x}{2}+cos^{2}\frac{x}{2}$